Removing iron from materials



Patented Jan. 20, 193i UNITED STATES PA NT OFFI E wrmmmr onus, or LuDwIesmEN-oN-rnE-anrna GERMANY, Assmnor. no I. e.

FARBENINDUSTRIE .AKTIENGESELLSCEAFT, OF FRANKFORT-ON-THE-MAIN, GEB- MANY, A CORPORATION OF GERINIZANY,

REMOVING IRON FROM MATERIALS No Drawing. Application filed October 1, 1925, Serial'll'o. 59,967, and in Germany October 4, i924;

- The present invention'relates to a process for theremoval of iron from materials and Y to render them more suitable for industrial purposes. Many materials, especially ores suchfor exampleas bauxite, titanic iron ore and others, contain a greater or lesser. amount of an admixture of iron mostly in the form of iron oxid which is very undesirable for the use of such materials for further treatment.

I have now found that iron can be removed either completely or to a large extent by treating the materials containing iron oxid with a current of carbon monoxid at an elevat-ed pressure of say 10 atmospheres or more and at elevated temperatures generally ranging from about 3100 degress to M0 degrees centigrade. Theiron oxid contained in the material. is first reduced to metallic iron and then converted into iron carbonyl in which form the iron can be easily removedfrom the materials. Any treatment with acids or other liquids is hereby rendered superfluous.

The treatment with carbon inonoiiid can be eflected in any suitable manner but it is preferable to employ a rapid current or carbon monozrid of suficient speed to take along all of the iron carbonyl formed and to avoid the deposition of liquid iron carbonyl in the ma-- ing for the subsequent production of iron carbonyl or it may be efiected with another reducing gas and under considerably difierent conditions. The iron carbonyl formed or the gases containing it may be decomposed treatment of materials to be, freed. from their iron content. The iron obtained by the said decompgsition of .iron carbonyl is of a high purity and in view thereof the present Bauxite containin iron oxid is heated to 250 degrees centi'gra e an'd water gas passed over the material at a pressure of 100 atmospheres. I After continuing the treatment for a sufficient length of time the residue'contalns may also be subiected to a separate reducexamples will serve to-il1u s-.

X tron treatment with reducing gases at a more elevated temperature with or Without employing increased pressure, prior to the aforesaid treatment. l

Example 2 100 lbs. of groundititaniferous iron sand with about 25.2 per cent of iron are first reduced by means of a current of dry hydrogen at ordinary pressure and at 909 degrees centigrade llOI about 13 hours. Thereupon the reduced mass is subjected to treatment with carbon monoxid at 200 degrees Centigrade and 200 atmospheres. In the course of an hour 81.5 lbs. of iron carbonyl are formed and in the course of three more hours an additional quantity of about 4.4 lbs. of iron carbonyl. lln this manner 97 .5 per cent of the iron contained in the titaniferous ore'is obtained in the form of iron carbonyl which is condensed in a suitable receiver. The residual ore contains only Ostlper cent of iron. In view thereof it can be worked up in a considerably cheaper and simpler way than the original ores for example when pure titanic acid is to be produced b decomposition with sul- Ewample a 100 lbs. of roastedpyrites with 54.5 per cent of ironand 3.08 per cent of copper are reduced with hydrogen at 5.00 degrees centigrade for 12 hours. The mass is then treated furic. acid and su equent hydrolysis of the titanium sulfate formed- #5 only a small amount of iron. The bauxite with a currentof carbon monoxid at 200 degrees centigrade and 200 atmospheres whereby per cent of the iron content are volatilized in the form of 181 lbs. of iron carbonyl. A residue of 8 lbs. is left which contains 38.4 per cent of copper and in view of this highpercentage can be readily Worked up to obtain metallic copper.

I claim: 1

The process for removing iron from bauxite containing iron, which comprises acting on the said bauxite With water gas at a temperature of about 250 C. and a pressure of about atmospheres and removing the iron carbonyl formed.

In testimony whereof I have hereunto set my hand.

WILHELM GAUS. 

